Pulverized, particulate clays, known in the art as fuller's earth or fuller's earth clays, are well-known for their oil and water sorbing properties and for their deodorizing characteristics. As a result, these clays have various industrial and household uses such as for the sorption of oil, grease and the like from floors and elsewhere where such materials represent a safety hazard. In addition, because of their water sorbing and deodorizing characteristics, fuller's earths have been found particularly useful in animal toilet applications, e.g., as a cat box sorbent. Another advantage of fuller's earth clays is their relatively low bulk densities of about 0.4 to about 0.9 kilograms per liter (kg/l) allows the use of relatively light weight sorbents.
Although fuller's earths have excellent sorbing and deodorizing characteristics, their use suffers from several cost-related difficulties. For example, fuller's earth clay deposits in sufficient quantities for commercialization occur only in six locations, five of which are in the United States, with the sixth being in Spain. Thus, large shipping expenses are encountered when world-wide product distribution is sought. Shipping expenses also present a problem within the United States because most of the commercialized deposits occur from southern Illinois through northern Florida, with one deposit in southern California and another in central Texas. Thus, relatively long range shipments are required to distribute the clays even within the United States.
Several methods have been tried to minimize the expense concomitant with the use of fuller's earths by preparing synthetic sorbing and deodorizing compositions from materials which are more readily available. Compositions based upon hydrated commercial grade plaster, calcium sulfate dihydrate, and their methods of manufacture, which are useful replacements for fuller's earth clays as particulate sorbents are exemplified by the teachings of commonly owned U.S. Pat. Nos. 4,163,674, 4,183,763 and 4,264,543. However, while the synthetic sorbtive granules can replace fuller's earth clays as sorbents for oil, water, excreted body fluids and like liquids, it has been found that the effectiveness of synthetic sorptive granules can be further enhanced by admixtures of such synthetic sorptive granules with particulate clay.